Network system and method for setting volume group in the network system

ABSTRACT

Disclosed is a method for setting virtual volume groups in a storage network system. The system includes a lower storage apparatus, host computers, an upper storage apparatus, and an administrative server. The method for setting virtual volume groups, executed by the administrative server, includes the steps of acquiring information on the real volumes, and port information on the physical devices in which the real volumes reside, creating virtual volumes being linked to the real volumes, based on the information on the real volumes, forming one or more virtual volume groups by combining the virtual volumes, based on the port information, in such a way that a relation between the virtual volumes and the virtual volume group are identical to a relation between the real volumes and the physical devices, and establishing the created virtual volume groups in the upper storage apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Patent Application2005-046423 filed on Feb. 23, 2005, the disclosure of which isincorporated herein by reference.

BACKGROUND

The present invention relates to a method for setting one or morevirtual volume groups in a storage network system.

A technique of virtual hardware has advanced. This technique allows auser to use hardware that is not actually present in an apparatus as ifthis hardware were present in the apparatus.

It is assumed that a first apparatus has a virtual device and a secondapparatus has a physically existing device (thereinafter, called“physical device”). To apply the virtual technique to these apparatuses,a link is typically established therebetween, so that a user can accessthe physical device through the virtual device. Once receiving a requestfor using the virtual device from a user through a user terminal, thefirst apparatus enables the user to utilize the physical device via thelink. In this case, the first apparatus serves as an intermediatebetween the user terminal and the second apparatus.

Referring to FIG. 15A, a storage apparatus R1 uses physical volumes of astorage apparatus R2 as virtual volumes. The storage apparatus R2 hasthree physical (or real) volumes (LUs 5, 6 and 7). The storage apparatusR1 uses two of them (LUs 5 and 6) as virtual volumes, and enables a userto use the storage apparatus R2 as if the virtual volumes were stored inthe storage apparatus R1. The storage apparatus R1 integrates thevirtual volumes into a single volume group AG 1. Note that this volumegroup is constituted by a bundle of virtual volumes integrated inaccordance with conditions of a computer.

When the virtual volume group is created, the virtual volumes are notalways integrated into a large single volume group, but the size of thevirtual volume group can be determined flexibly depending on anapplication. To give an example, Japanese Unexamined Patent ApplicationPublication 2004-178253 discloses a method for integrating the volumes,depending on disk specifications such as the type of a disk or the levelof Redundant Arrays of Inexpensive Disks (RAID), when virtual volumesare created.

However, in conventional techniques, physical and virtual volumes arenot distinguished from each other. This may be advantageous for someapplications, but in general, the distinction is essential to make fulluse of hardware characteristics, such as achieving load distribution.

Referring to FIG. 15B, four virtual volumes (LUs 5, 6, 7 and 8) areallocated to two physical disks in the storage apparatus R2. The storageapparatus R1 integrates virtual volumes into the two volume groups (AGs3 and 4).

The real volumes to be linked by the virtual volumes (LUs 5 and 6) ofthe AG 3 are allocated to the single disk, whereas the real volumescorresponding to the virtual volumes (LUs 7 and 8) of the AG 4 areallocated to the different disks. Accordingly, it is assumed that twoprocesses are assigned to the volume groups AGs 3 and 4, respectively.In this state, if the volume groups AGs 3 and 4 are used at the sametime, then load distribution cannot be achieved. This is because the LUs5, 6 and 7 are present in the single physical disk.

This disadvantage is due to the fact that the volume groups are not setbased on the arrangement of the real volumes in each physical disk. Asin the above conventional techniques, when the volume groups are setbased on disk specifications such as the type of disk or the level ofthe RAID, information on physical disks cannot be obtained. Accordingly,when the volume groups are assigned to real volumes, the virtual volumeswith a heavy load may be assigned to the real volumes in the singlephysical disk. Consequently, the access is prone to be concentrated onthe single physical disk, thereby deteriorating the access capability ofthe system composed of the storage apparatuses.

SUMMARY

Taking the above disadvantage into account, the present invention hasbeen conceived. An object of the present invention is to provide astorage system in which volume groups, each being composed of virtualvolumes, are set appropriately in terms of load distribution. Anadditional object of the present invention is to provide a method forsetting volume groups in the above storage system.

According to an aspect of the present invention, in a storage networksystem constituted of: at least one lower storage apparatus in which oneor more physical devices, each of which has one or more real volumes,are arranged; one or more computers, each being capable of using data inthe volumes, for providing data access to the corresponding realvolumes; at least one upper storage apparatus for conducting mediationof the data access; and an administrative server for setting themediation, a method for setting virtual volume groups through thestorage network system, executed by the administrative server, themethod including:

(a1) acquiring information on the real volumes, and port information onthe physical devices in which the real volumes reside;

(b1) creating virtual volumes being linked to the real volumes, based onthe information on the real volumes;

(c1) forming one or more virtual volume groups by combining the virtualvolumes, based on the port information, in such a way that a relationbetween the virtual volumes and the virtual volume groups in which thevirtual volumes reside are identical to a relation between the realvolumes and the physical devices in which the real volumes reside; and

(d1) establishing the created virtual volume groups in the upper storageapparatus.

According to another aspect of the present invention, a storage networksystem including:

(a2) at least one lower storage apparatus provided with one or morephysical devices, each of which has one or more real volumes;

(b2) one or more computers each being capable of using data in thevolumes and for providing data access to the corresponding real volumes;

(c2) at least one upper storage apparatus for conducting mediation ofthe data access; and

(d2) an administrative server for setting the mediation, theadministrative server comprising functions of:

-   -   (a3) acquiring information on the real volumes, and port        information on the physical devices in which the real volumes        reside;    -   (b3) creating one or more virtual volumes being linked to the        real volumes, based on the information on the real volumes;    -   (c3) forming one or more virtual volume groups by combining the        virtual volumes, based on the port information, in such a way        that a relation between the virtual volumes and the virtual        volume groups in which the virtual volumes reside are identical        to a relation between the real volumes and the physical devices        in which the real volumes reside; and    -   (d3) establishing the created virtual volume groups in the upper        storage apparatus.

Other objects, features and advantages of the present invention willbecome apparent upon reading the following specification and claims whentaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For more complete understanding of the present invention and theadvantages hereof, reference is now made to the following descriptiontaken in conjunction with the accompanying drawings wherein:

FIG. 1 is a view for explaining a configuration of volume groupsaccording to one embodiment of the present invention;

FIG. 2 is a block diagram depicting hardware of a storage network systemaccording to one embodiment of the present invention;

FIG. 3 is a view depicting a configuration of a typical storageapparatus;

FIG. 4 is a detail block diagram depicting the storage administrativesystem;

FIG. 5 is a view depicting a configuration of an intermediate settingfile according to one embodiment of the present invention;

FIG. 6 is a view depicting a configuration of an intermediateinformation DB according to one embodiment of the present invention;

FIG. 7A is a view depicting a configuration of a virtual volume group DB(administrative server side) according to one embodiment of the presentinvention;

FIG. 7B is a view depicting a configuration of the virtual volume groupDB (upper storage apparatus side);

FIG. 8A is a view depicting a configuration of a storage apparatus DBaccording to one embodiment of the present invention;

FIG. 8B is a view depicting another configuration of the storageapparatus DB;

FIG. 9 is a view depicting a configuration of a port information DBaccording to one embodiment of the present invention;

FIG. 10A is a view depicting a configuration of a volume group DB (lowerstorage apparatus side) according to one embodiment of the presentinvention;

FIG. 10B is a view depicting another configuration of the volume groupDB (upper storage apparatus side);

FIG. 11 is a flowchart showing a main routine of a method for settingvolume groups according to a first embodiment of the present invention;

FIG. 12A is a flowchart showing a routine in which a storage apparatuscollects information, according to the first embodiment;

FIG. 12B is a flowchart showing another routine in which the storageapparatus collects information;

FIG. 13 is a flowchart showing a routine in which volume groups arecreated, according to the first embodiment;

FIG. 14A is a flowchart showing a main routine of a method for settingvolume groups according to a second embodiment of the present invention;

FIG. 14B is a flowchart showing another main routine of the method forsetting volume groups;

FIG. 15A is a view for explaining virtual volumes in storageapparatuses; and

FIG. 15B is another view for explaining virtual volumes in storageapparatuses.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS OF THE INVENTION

A detail description will be given below, of a storage system and amethod for setting volume groups in the storage system, according tofirst and second embodiments of the present invention.

Referring to FIG. 1, an upper storage apparatus 2 has virtual volumescorresponding to real volumes (LUs 1, 2 and 3) within physical devices(AG1-1 and AG1-2) in a lower storage apparatus 3. These virtual volumesare gathered to make up two virtual volume groups. Herein, a virtualvolume group is denoted by a group which is composed of multiple virtualvolumes, and which is created in accordance with a request from acomputer. In this case, the upper storage apparatus 2 has the virtualvolume groups AG#5-1 and AG#5-2, and their configuration is similar tothat of the physical devices in the lower storage apparatus 3.

Because of the above configurations, the volume groups in the upperstorage apparatus 2 are linked to the real volume groups in the lowerstorage apparatus 3 in a one-to-one relationship. This realizes loaddistribution, because the real volume groups within the single physicaldevice in the lower storage apparatus 3 are never used at the same time,even if multiple virtual volume groups in the upper storage apparatus 2are used simultaneously. Furthermore, the upper storage apparatus 2 hasa physical device AG 1-3 which may be available to a user, in additionto the volume groups.

First Embodiment

Referring to FIG. 2, a storage network system according to a firstembodiment of the present invention includes an administrative server 1,host computers 4, an upper storage apparatus 2 and a lower storageapparatus 3.

Each of the administrative server and the storage apparatuses 2 and 3 iscomposed of a memory for use in a computing process, a processor forperforming the computing process, and other components. The memory maybe a random access memory (RAM) The processor has a central processingunit (CPU), which executes a program recorded on the memory in order tocarry out the computing process. The program and data handled by theprogram are stored in a storage section 30 (see FIG. 4). Each of theadministrative server and the storage apparatuses 2 and 3 furtherincludes an internal bus interconnecting its internal components. Thestorage section 30 may be a physical device selected from one of a harddisk drive (HDD), a magnetic disc, an optical disc, a magneto-opticaldisc, and a magnetic tape.

A detail description will be given below, of individual functions of theadministrative server and the storage apparatuses 2 and 3. The lowerstorage apparatus 3 has real volumes to be made virtual. The upperstorage apparatus 2 mediates between the real volumes of the lowerstorage apparatus 3 and the host computers 4, based on volumeinformation acquired from the lower storage apparatus 3. The realvolumes in the lower storage apparatus 3 are linked to virtual volumesof volume groups in the upper storage apparatus 2. Furthermore, a useraccesses the virtual volume groups through each host computer 4. Thishost computer 4 can use data in the volumes in the upper and lowerstorage apparatuses 2 and 3. As a result, the user can access the realvolumes of the lower storage apparatus 3 indirectly.

The administrative server 1 sets the upper storage apparatus 2 withreference to an intermediate setting file 32 (see FIG. 5) to which anadministrator has inputted information. This enables the upper storageapparatus 2 to mediate between the host computers 4 and the lowerstorage apparatus 3. Furthermore, the administrative server 1 includesan input device, an output device and a communication port(administration purpose). The input device receives information to beinputted to the intermediate setting file 32. The output device appliesthe information from intermediate setting file 32 to the administrator.The communication port (administration purpose) serves as a networkinterface for notifying the intermediate setting to the upper storageapparatus 2.

In this system, all storage apparatuses can be classified into twotypes; one is the upper storage apparatus 2 and the other is the lowerstorage apparatus 3. Each host computer 4 is series-connected to theupper storage apparatus 2 and the lower storage apparatus 3 in thisorder. The mediation of the volumes is aimed at making a user feel as ifthe volumes of the lower storage apparatus 3 were those of the upperstorage apparatus 2. Upon mediation, even if the upper storage apparatus2 is a high-performance model but the lower storage apparatus 3 is alow-performance model, then the lower storage apparatus 3 can utilizethe function and the powerful, high capacity cash of the upper storageapparatus 2. This results in the effective utilization of an old type orlow-performance storage apparatus.

Continuing to FIG. 2, the upper storage apparatus 2 includes three typesof communication ports. One type is connected to the host computer 4,and serves as an interface for communication with the host computer 4.Another type serves as an interface for communication with the lowerstorage apparatus 3. An additional type serves as an interface forcommunicating administrative data. Since being not connected to the hostcomputers 4 directly, the lower storage apparatus 3 does not have anycommunication port for the host computer 4. Moreover, the upper storageapparatus 2 further includes physical disks, a memory, and a controllerfor managing an internal process.

The lower storage apparatus 3 has a configuration similar to that of theupper storage apparatus 2. However, lower storage apparatus 3 needs tohave neither of the communication ports for the host computer, nor thefunction of possessing real volumes of other storage apparatuses asvirtual volumes. Note that, when the real volumes of the lower storageapparatus 3 do not function as the virtual volumes of the upper storageapparatus 2, the real volumes does not have to be linked thereto.

FIG. 3 shows a structure of a typical storage apparatus. This storageapparatus may be applied to the upper and lower storage apparatuses 2and 3. The storage apparatus can use multiple internal physical disks torealize a RAID system. In addition, the group of the physical disks thatrealize the RAID system is called “array group”. In this figure, thefour physical disks create an array group, and the two volumes LUs 1 and2 are allocated to this array group.

Referring to FIG. 4, the administrative server 1 includes a controlsection 10 which executes a program, and the storage section 30 whichstores the program and related data. The control section 10 is composedof a port information acquisition unit 12, a volume informationacquisition unit 14, a volume group generation unit 16, a volume groupsetting unit 18 and an intermediate instruction unit 20. The storagesection 30 is composed of the intermediate setting file 32, anintermediate information DB 34, a virtual volume group DB 36 and astorage apparatus DB 38.

The function of both the port information acquisition unit 12 and thevolume information acquisition unit 14 is to collect information on thestorage apparatuses. Specifically, the port information acquisition unit12 collects port setting information on the upper and lower storageapparatuses 2 and 3. The volume information acquisition unit 14 acquiresvolume information on the lower storage apparatus 3.

The functions of the volume group generation unit 16, of the volumegroup setting unit 18, and of the intermediate instruction unit 20 areto make the upper storage apparatus 2 mediate between the host computer4 and the lower storage apparatus 3, based on the information on thestorage apparatuses. Specifically, the volume group generation unit 16creates virtual array group(s) of the upper storage apparatus 2, basedon array group(s) of the lower storage apparatus 3. The volume groupsetting unit 18 establishes the virtual array group(s) of the upperstorage apparatus 2, based on the array group(s) of the lower storageapparatus 3. The intermediate instruction unit 20 directs the upperstorage apparatus 2 to mediate through the array groups beingestablished by the volume group setting unit 18.

Referring to FIG. 5, the intermediate setting file 32 containsinformation on the mediation of the volume groups, which has beeninputted by the administrator. Alternatively, this mediation informationmay be created by the administrator through a graphical user interface(GUI).

The intermediate setting file 32 contains upper storage apparatusinformation and intermediate volume information. The upper storageapparatus information has an upper storage apparatus ID, a virtualvolume ID, and an intermediate port ID. The intermediate volumeinformation has a port address of the lower storage apparatus 3 and anintermediate volume ID. By coupling together the port address and theintermediate volume ID, the volumes of each storage apparatus connectedto a network can be identified uniquely.

Referring to FIG. 6, the intermediate information DB 34 contains upperstorage apparatus information and intermediate volume information. Theupper storage apparatus information has an upper storage apparatus ID, avirtual volume ID, an intermediate port ID, and a virtual volume groupID.

The intermediate volume information has:

-   (a4) a storage apparatus ID, which indicates the ID of a storage    apparatus having an intermediate volume;-   (b4) a port address, which indicates the address of port of the    lower storage apparatus 3 for connection with an intermediate    volume;-   (c4) an intermediate volume ID;-   (d4) a volume ID;-   (e4) a RAID level, which indicates the level of RAID system of each    intermediate volume;-   (f4) a disk type, which indicates the disk type of each intermediate    volume; and-   (g4) an array group, which indicates the array group in which each    intermediate volume resides.

Referring to FIG. 7A, the virtual volume group DB 36 contains an upperstorage apparatus ID that indicates the ID of the upper storageapparatus 2, a virtual volume group ID that indicates the ID of avirtual volume group in the upper storage apparatus 2, a lower storageapparatus ID that indicates the ID of the lower storage apparatus 3, andan array group ID that indicates the ID of each array group of the lowerstorage apparatus 3.

Referring to FIG. 8A, a storage apparatus DB 38 contains a storageapparatus ID, and a port address that indicates the address of each portof the storage apparatus.

Referring back to FIG. 4, the upper storage apparatus 2 includes avolume group intermediate unit 40, a virtual volume group DB 36, a portinformation DB 44 and a volume group DB 46. The lower storage apparatus3 includes a port information DB 44 and a volume group DB 46.

Referring to FIG. 7B, the virtual volume group DB 36 contains a virtualvolume group ID that indicates the ID of each virtual volume group ofthe upper storage apparatus 2.

Referring to FIG. 9, the port information DB 44, from which the portinformation acquisition unit 12 acquires port information, contains aport number, a port address, an intermediate volume ID, and a volume ID.

Referring to FIG. 10A, the volume group DB 46 of the lower storageapparatus 3 applies volume information to the volume informationacquisition unit 14 in response a request therefrom. The volume group DB46 contains a volume ID, a RAID level, a disk type, and an array group.

Referring to FIG. 10B, the volume group DB 46 contains information onthe virtual group being linked to the real volume of the lower storageapparatus 3, in addition to information on real volumes in the lowerstorage apparatus 3 as shown in FIG. 10A.

Concretely, the volume group DB 46 of the upper storage apparatuscontains:

-   (a6) a volume ID;-   (b6) a RAID level, which indicates the level of RAID system of each    array group;-   (c6) a disk type, which indicates the disk type of each array group;-   (d6) a volume group, which indicates an volume group in which each    volume resides;-   (e6) a virtual volume flag, which indicates whether volumes are    virtual or not;-   (f6) an intermediate port for use in connection with the    intermediate volumes;-   (g6) a port address of the lower storage apparatus 3 for connection    with intermediate volumes; and-   (h6) an intermediate volume ID.

The volume group DB 46 (see FIGS. 10A and 10B) contains information onthe relation between volumes and volume groups in which the volumesreside. By referring to this information, all volumes in the volumegroup can be identified.

FIG. 11 shows a routine executed when an administrator sets the virtualvolume group, with reference to the intermediate setting file 32. Byexecuting this routine, the upper storage apparatus 2 can have thevolume groups equivalent to the physical disks of the lower storageapparatus 3. Moreover, the administrator can assign the virtual groupsof the upper storage apparatus 2 to the host computers 4, based on thearrangement of the physical devices.

First, the control section 10 reads the information from theintermediate setting file 32 and, then stores it in the intermediateinformation DB 34 (S101).

Second, the port information acquisition unit 12 of the control section10 collects port information from each record of the intermediateinformation DB 34. In addition, the volume information acquisition unit14 collects volume information from each record of the intermediateinformation DB 34. The control section 10 searches the intermediateinformation DB 34 for any record containing no information (port andvolume information) (S102).

If any record containing no information is found (“YES” in S102), thenport information acquisition unit 12 collects port information from thelower storage apparatus 3 (S111). Subsequently, the volume informationacquisition unit 14 collects volume information from the lower storageapparatus 3 (S112), and the control section 10 then allows processing toreturn to S102.

Otherwise (“NO” in S102), the volume group generation unit 16 createsvirtual volume groups (S121). Subsequently, the control section 10establishes the volume groups (S122) and, then directs the upper storageapparatus 2 to mediate through the volume groups (S123).

FIG. 12A shows a routine in which the port information acquisition unit12 collects the port information (S111). This routine will be describedbelow.

First, the port information acquisition unit 12 extracts a port addressfrom a first record out of the records containing no port information inthe intermediate information DB 34. Subsequently, the port informationacquisition unit 12 searches the storage apparatus DB 38 for the ID ofthe lower storage apparatus which has a port address identical to theextracted port address (S201). The found ID represents the ID of thelower storage apparatus 3.

The port information acquisition unit 12 sends a request for portinformation to the lower storage apparatus 3 having an ID identical tothe found ID (S202). This request contains the ID of the sending sourceand the extracted port address.

Once receiving this request, the lower storage apparatus 3 searches theport information DB 44 for information on a port that has a port addressidentical to that contained in the received request. The lower storageapparatus 3 then sends back the found information to the portinformation acquisition unit 12.

Upon reception of the port information from the lower storage apparatus3, the port information acquisition unit 12 extracts a volume ID fromthe received port information. Subsequently, the port informationacquisition unit 12 stores the extracted volume ID as a volume ID of theintermediate volume information on the first record having no portinformation in the intermediate information DB 34 (S203).

FIG. 12B shows a routine in which the volume information acquisitionunit 14 collects the volume information (S112).

First, the volume information acquisition unit 14 extracts a portaddress from a first record out of the records containing no volumeinformation in the intermediate information DB 34. Subsequently, thevolume information acquisition unit 14 searches the storage apparatus DB38 for the ID of the storage apparatus which has a port addressidentical to the extracted port address (S301). The found ID representsthe ID of the lower storage apparatus 3.

Second, the volume information acquisition unit 14 sends a request forvolume information to the lower storage apparatus 3 having an IDidentical to the found ID (S302). The volume information contains theIDs of a sending source and of a volume.

Note that the ID of the sending source is that of the administrativeserver 1, and the ID of the volume is an identifier of the first recordcontaining no volume information.

Once receiving this request, the lower storage apparatus 3 searches thevolume group DB 46 for information on a volume corresponding to theidentifier. The lower storage apparatus 3 then sends back the foundinformation to the volume information acquisition unit 14.

The volume information acquisition unit 14 extracts the RAID level, disktype and volume group from the received volume information and, thenstores them as the volume information on the first record containing novolume information in the intermediate information DB 34 (S303).

FIG. 13 shows a routine in which volume groups are created (S121). Thisroutine will be described below.

First, the volume group generation unit 16 searches the intermediateinformation DB 34 for an untreated record (S401). If any untreatedrecord is found (“YES” in S401), then the volume group generation unit16 executes the following routine for the found record.

The volume group generation unit 16 searches the virtual volume group DB36 for a record having the IDs of the upper storage apparatus, of thelower storage apparatus and of the virtual volume group that are allidentical to those in the virtual volume group DB 36, respectively.

If no records are found (“NO” in S402), then the ID of the virtualvolume group of the first record in the intermediate information DB 36is newly assigned (S403). This new ID needs to differ from all theexisting virtual volume groups IDs in the virtual volume group DB 36.The new IDs may be incremented by 1 in order.

Otherwise (“YES” in S402), the virtual volume group of the correspondingrecord in the intermediate information DB 34 is assigned to that of theuntreated record in the virtual volume group DB 36 (S404).

This routine returns to S401. If all the records in the intermediateinformation DB 34 undergoes the process already (“NO” in S401), then thevolume group generation unit 16 terminates this routine. In this way,the volume group generation unit 16 executes the routine.

A concrete description will be given below, of a routine (S122) in whichthe volume group setting unit 18 sets the virtual volume groups.

Once receiving a request for setting of the virtual volume groups, theupper storage apparatus 2 updates its virtual volume group DB 36,allowing the virtual volume groups to be added or deleted. This requestincludes setting category designating the addition or delete of thevirtual volume groups, and the information on the virtual volume groupssuch as ID.

The volume group setting unit 18 sends the request to the upper storageapparatus 2 for each record of the virtual volume group DB 36 of theadministrative server 1. This request is created based on theinformation on the records of the virtual volume group DB 36. The volumegroup setting unit 18 establishes the IDs of all the virtual volumegroups of the virtual volume group DB 36 in the upper storage apparatus2.

Continuously, a detail description will be given below, of a routine(S123) in which the intermediate instruction unit 20 directs the upperstorage apparatus to mediate through the volume groups.

The intermediate instruction unit 20 sends instructions for mediatingthrough the volume groups to all the upper storage apparatuses 2 onwhich information has been assigned to the records of the intermediateinformation DB 34.

First, the intermediate instruction unit 20 sends an intermediaterequest to the upper storage apparatus 2 for each record of theintermediate information DB 34. This request is created based on thecontents of records of the intermediate information DB 34.

This request includes: the ID of the virtual volume; the RAID level ofthe virtual volume; the disk type of the virtual volume; the volumegroup of the virtual volume; the intermediate port used forcommunication with the real volume; the port address used forcommunication with the real volume; and the ID of the real volume.

In the intermediate request, the intermediate instruction unit 20designates the following items in the upper storage apparatusinformation of the intermediate volume information DB 34:

-   (a7) the volume ID;-   (b7) the RAID level;-   (c7) the type of the disk;-   (d7) the virtual volume group;-   (e7) the ID of the intermediate port;-   (f7) the port address; and-   (g7) the intermediate volume ID.

Once receiving the request from the intermediate instruction unit 20,the upper storage apparatus 2 updates the volume group DB 46, so thatthe intermediate process is ready.

As described above, the description has been given, of the storagenetwork system and the method for setting volume groups through thestorage network system, according to the first embodiment.

With this system and method, virtual volume groups composed of virtualvolumes can be set appropriately in terms of load distribution.

Second Embodiment

Next, a detail description will be given below, of a storage networksystem and a method for setting volume groups through the storagenetwork system, according to a second embodiment of the presentinvention. The second embodiment differs from the first embodiment as totiming of inputting information in the intermediate setting file 32. Inthe first embodiment, before the information on the storage apparatusesare collected (S111 and S112), the intermediate setting file 32 are read(S101), as shown in FIG. 10. In contrast, in the second embodiment,after the information on the storage apparatuses are collected (S105 andS106), the intermediate setting file 32 are read (S109), as shown inFIGS. 13A and 13B. This enables an administrator to create theintermediate setting file 32 with reference to the information on thestorage apparatuses.

Since the second embodiment is similar to the first embodiment, the samereference numerals are given to the same parts as those alreadydescribed in the first embodiment. Therefore, duplicate description isomitted, and only different points will be described. The concretedifferent points are a program stored in the hard disk, and informationin the data base in the administrative server 1.

In this embodiment, the administrative server 1 acquires information,such as port or volume information, in response to the instruction ofthe administrator and, then outputs the acquired information to theadministrator. Furthermore, the administrative server 1 readsinformation from the intermediate setting file 32, to which data hasbeen inputted by the administrator, in response to the instruction ofthe administrator and, then directs the upper storage apparatus 2 tomediate through the volume groups.

In this embodiment, the virtual volume groups in the upper storageapparatus 2 can be created so as to have the arrangement equivalent tothat of the physical devices of the lower storage apparatus 3. Thisenables the administrator to assign the virtual volume of the upperstorage apparatus 2 to the host computer 4, based on the arrangement ofthe physical disks.

In FIG. 8B, the storage apparatus DB 38 stores the port information foreach record. Concretely, the storage apparatus DB 38 contains a storageapparatus ID, a port number, a port address, an intermediate group ID, avolume ID, a RAID level, a disk type, and the volume group.

FIGS. 14A and 14B show main routines of the second embodiment.

A detail description will be given below, of the routines in whichinformation on the storage apparatuses is collected.

First, an administrator executes a command to activate the controlsection 10 of the administrative server 1 (S104).

Second, the port information acquisition unit 12 of the control section10 collects the port information from the lower storage apparatus 3(S105). Specifically, the port information acquisition unit 12 refers tothe storage apparatus ID of the storage apparatus DB 38 in the lowerstorage apparatus 3 and, then sends a request for the port informationto all the lower storage apparatuses 3 registered in the storageapparatus DB 38.

Once receiving this request, each storage apparatus sends back the portinformation stored in the port information DB 44 to the administrativeserver 1. This port information contains the ID of the storage apparatusas a header, which indicates a sending source. The port informationacquisition unit 12 receives the port information and, then sores it inthe storage apparatus DB 38 for each record.

The stored port information contains the ID of the storage apparatus, aport number, a port address, the ID of an intermediate volume, and theID of a volume.

Next, the volume information acquisition unit 14 of the control section10 collects volume information from the storage apparatus (S106).

The volume information acquisition unit 14 refers to the storageapparatus ID stored in the storage apparatus DB 38. Subsequently, thevolume information acquisition unit 14 sends a request for volumeinformation to all the lower storage apparatuses 3 registered in thestorage apparatus DB 38.

Once receiving the request, each storage apparatus 3 sends back thevolume information, which is stored in the volume group ID in a formshown in FIG. 12, to the administrative server 1. The port informationcontains the ID of the lower storage apparatus 3 as a header, whichindicates a sending source.

The volume information acquisition unit 14 searches the storageapparatus DB 38 for records having the storage apparatus IDs and thevolume IDs identical to those of the received volume information.

A detail description will be given below, of a process in which thevolume information acquisition unit 14 stores the volume information.The volume information acquisition unit 14 executes this routine everytime acquiring the volume information.

The volume information acquisition unit 14 searches the storageapparatus DB 38 for the records having the sending source informationand the ID of the volume identical to those of the received volumeinformation. Further, the volume information acquisition unit 14 storesthe RAID level, disk type and volume group that are all contained in thefound records.

Finally, the control section 10 outputs the information stored in thestorage apparatus DB 38 to the output device (S107)

With the above-described routines, the administrator is capable ofacquiring the information on the storage apparatuses. Continuously, theadministrator can create the intermediate setting file 32, based on thestorage apparatus information. Furthermore, a routine in which themediation is directed is executed based on the created intermediatesetting file 32. This routine will be described with reference to FIG.14B.

Referring to this figure, the administrator first executes a command toactivate the control section 10 of the administrative server 1 (S108).Subsequent steps are shown as follows, although being identical tocorresponding steps shown in FIG. 11.

The administrative server 1 reads the intermediate setting file 32(S109). The volume group generation unit 16 creates the virtual volumegroups (S121). The control section 10 establishes the virtual volumegroups in the upper storage apparatus 2 (S122), and directs the upperstorage apparatus 2 to mediate through the virtual volume groups (S123).

With the above system and method, the administrator can understand theconditions of the volume groups, thus enabling appropriate intermediatethrough the volume groups.

Up to this point, the first and second embodiments have been described.Note that the methods of the first and second embodiments may beimplemented in a computer readable recording medium. In this case, thecomputer readable medium stores a program that executes these methods.Moreover, it is obvious that the present invention is not limited tothese embodiments.

To give an example, although the administrative server 1 and the upperstorage apparatus 2 are separated from each other in the aboveembodiments, they may be integrated. In this case, the upper storageapparatus 2 may be provided with a memory in which a program to beexecuted by the administrative server 1 is stored.

Furthermore, the two networks of FIG. 2 (administrative andcommunication purposes) may be integrated.

Moreover, in the embodiment, the number of the upper or lower storageapparatuses is one, as shown in FIG. 2, but the present invention is notlimited thereto. Alternatively, the number of the storage apparatusesmay be plural number.

In conclusion, the method of the above-described embodiment can achievethe creation of virtual volume groups in a storage system which areequivalent to physical disks of another storage system. Accordingly, anadministrator can recognize the physical relation of the virtualvolumes, thereby making it possible to set the virtual volume groupsappropriately in terms of load distribution.

From the aforementioned explanation, those skilled in the art ascertainthe essential characteristics of the present invention and can make thevarious modifications and variations to the present invention to adaptit to various usages and conditions without departing from the spiritand scope of the claims.

1. A storage network system including at least one lower storageapparatus in which one or more physical devices, each of which has oneor more real volumes, are arranged, one or more computers, each beingcapable of using data in said volumes, for providing data access to thecorresponding real volumes, at least one upper storage apparatus forconducting mediation of the data access, and an administrative serverfor setting the mediation, a method for setting virtual volume groupsthrough the storage network system, executed by the administrativeserver, the method comprising: acquiring information on the realvolumes, and port information on the physical devices in which the realvolumes reside; creating virtual volumes being linked to the realvolumes, based on the information on the real volumes; forming one ormore virtual volume groups by combining the virtual volumes, based onthe port information, in such a way that the virtual volumes and thevirtual volume groups in which the virtual volumes reside have avirtual-volume-to-virtual-volume-group configuration which is identicalto a real-volume-to-physical-device configuration of the real volumesand the physical devices in which the real volumes reside; andestablishing the created virtual volume groups in the upper storageapparatus.
 2. The method according to claim 1, wherein in acquiring theinformation, the information on the real volumes and the portinformation are outputted.
 3. The method according to claim 1, whereinin acquiring the information, at least information about the realvolumes that are designated by setting information being inputted isacquired.
 4. The method according to claim 1, wherein each of thephysical devices comprises a hard disk, a magnetic disc, an opticaldisc, a magneto-optical disc, and a magnetic tape.
 5. A computerreadable recording medium for storing a program that executes the methodof claim
 1. 6. A storage network system comprising: at least one lowerstorage apparatus provided with one or more physical devices, each ofwhich has one or more real volumes; one or more computers, each beingcapable of using data in said volumes, for providing data access to thecorresponding real volumes; at least one upper storage apparatus forconducting mediation of the data access; and an administrative serverfor setting the mediation, the administrative server comprisingfunctions of: acquiring information on the real volumes, and portinformation on physical devices in which the real volumes reside;creating one or more virtual volumes being linked to the real volumes,based on the information on the real volumes; forming one or morevirtual volume groups by combining the virtual volumes, based on theport information, in such a way that the virtual volumes and the virtualvolume groups in which the virtual volumes reside have avirtual-volume-to-virtual-volume-group configuration which is identicalto a real-volume-to-physical-device configuration of the real volumesand the physical devices in which the real volumes reside; andestablishing the created virtual volume groups in the upper storageapparatus.
 7. The network system according to claim 6, wherein theadministrative server comprises a function of outputting the informationon the real volumes and the port information.
 8. The network systemaccording to claim 6, wherein the administrative server comprises afunction of acquiring at least information about the real volumes thatare designated by setting information being inputted.
 9. The networksystem according to claim 6, wherein each of the physical devicescomprises a hard disk, a magnetic disc, an optical disc, amagneto-optical disc, and a magnetic tape.